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Fishery Bulletin 93(3). 1995 



Contours for sweep 1 of the 

 May-June survey of 1990 showed 

 a pattern of recent or ongoing 

 upwelling occurring off Point 

 Reyes and the Davenport area 

 (see Fig. 1 for place names) as 

 evidenced by the filaments of 

 higher salinity water projecting 

 seaward and shoreward impinge- 

 ment of lower salinity, more oce- 

 anic water (Simpson, 1987) at the 

 surface north of Point Reyes (Fig. 

 8). The contours for sweep 2 in- 

 dicated a reduction in offshore 

 transport due to upwelling, with 

 lower salinities closer to shore 

 (Fig. 8). The contours for sweep 

 3 showed upwelling activity oc- 

 curring off Point Reyes but not 

 off Davenport (Fig. 8). 



The contours for the May-June 

 survey of 1991 showed pronounced 

 seaward filaments off Point 

 Reyes and Davenport during 

 sweep 1, which indicated recent 

 or ongoing upwelling (Fig. 9). 

 During sweep 2, upwelling was still evident off 

 Davenport, but owing to problems with the 

 CTD, patterns off Point Reyes were not easily 

 discernible (Fig. 9). During sweep 3, there was a 

 relaxation of upwelling as evidenced by the lack 

 of seaward-projecting filaments of higher salin- 

 ity water (Fig. 9). 



The overlaid abundances of stages 2 and 5 

 showed that large abundances of stage-5 indi- 

 viduals of both species generally occurred 

 nearshore and could be found within centers of 

 upwelling (Figs. 8 and 9 off Davenport and 

 Monterey Bay; Fig. 9 off Point Reyes). In con- 

 trast, large numbers of stage-2 individuals of 

 both species were relatively more abundant in 

 the offshore transitional zone between coastal 

 water (nearshore, high salinity due to up- 

 welling) and oceanic water (offshore, low salin- 

 ity) (Figs. 8 and 9). In addition, large numbers 

 of stage-2 individuals were observed nearshore 

 in the area north of Point Reyes during sweep 

 1 of 1990 associated with the shoreward im- 

 pingement of oceanic water (Fig. 8). 



Although the effects of upwelling would be 

 expected to be most intense near the surface, 

 no significant differences in the abundances of 

 the metamorphic stages of either sanddab spe- 

 cies were observed between upwelling and non- 

 upwelling areas at the shallow trawl depth of 



